Discuss changes in taste, smell, and touch sensitivity in late adulthood

What will be an ideal response?

Reduced sensitivity to the four basic tastes—sweet, salty, sour, and bitter—is evident in many adults after age 60. Older adults also have greater difficulty recognizing familiar foods by taste alone. But no change in the number or distribution of taste buds occurs late in life, so this drop in taste sensitivity may be due to factors other than aging. Cigarette smoking, dentures, medications, and environmental pollutants can affect taste perception. When taste is harder to detect, food is less enjoyable, increasing the likelihood of dietary deficiencies. Flavor additives can help make food more attractive.
Besides enhancing food enjoyment, smell has a self-protective function. An aging person who has difficulty detecting rancid food, gas fumes, or smoke may be in a life-threatening situation. A decrease in the number of smell receptors after age 60 contributes to declines in odor sensitivity. Odor perception not only wanes but becomes distorted, a change that may promote complaints that "food no longer smells and tastes right." But older adults experiencing greater difficulty with verbal recall, including retrieval of odor labels, have greater difficulty with odor recognition tasks. So cognitive changes may make the decline in odor perception appear greater than it actually is.
Touch sensitivity is especially crucial for certain adults, such as the severely visually impaired reading Braille and people making fine judgments about texture. In later life, capacity to discriminate detailed surface properties and identify unfamiliar objects by touch declines. Waning of touch perception on the hands, especially the fingertips—believed to be due to loss of touch receptors in certain regions of the skin and slowing of blood circulation to the extremities—contributes. In addition, decrements in fluid abilities, especially spatial orientation, are influential. Fluid skills are strongly correlated with older adults' tactile performance.